1. Field of the Invention
The present invention relates to a suture comprising a drug-loaded polymer layer and a method of manufacturing the same, and more particularly, to a suture the surface of which is covered with film including a drug-loaded biodegradable polymer layer, or coated with a drug-loaded biodegradable polymer layer, and to a method of manufacturing the same.
2. Description of the Related Art
Sutures, which are necessary for sewing excised or incised sites during surgical operation, are a medical device for tying or binding tissue such as blood vessels, etc. Sutures are classified into non-absorbable sutures and absorbable sutures. Non-absorbable sutures are mainly used to sew tissue exposed to the outside, which can retain tensile strength for longer than the period of healing. Dissimilarly, for sewing internal organs, absorbable sutures are mainly used, which are biodegraded and absorbed by water or enzyme, avoiding the need of secondary anesthesia and operation to remove the sutures.
To avoid or minimize any complications at the sutured sites after a surgical operation, an anti-inflammatory or antibiotic drug is often orally administered. However, this method may not be effective because the drug would be delivered not only to the sites of interest but systemically to the whole body. Additionally, long term administration of an oral drug may cause a great deal of inconvenience and possible complications to patients.
Although many researchers have studied sutures in which drug is directly loaded, disadvantages exist in these studies in terms of the weakened mechanical strength, limited amount of the loaded drug, and inability to control drug delivery.
Specifically, R. Zurita et al. developed a method of loading ibuprofen as a model drug on conventional monofilament or multifilament absorbable sutures (Macromolecular Bioscience, 2006, 6, 767-775). In this article, the drug release profiles are varied with preparing conditions and the mechanical properties thereof are grasped, which resulted in the finding that the sutures coated by immersion in a solution including a drug and a polymer exhibited the undesirably decreased mechanical strength and limited amount of the loaded drug.
U.S. Pat. No. 6,878,757 discloses a suture coated with a mixture comprising antibiotics and a copolymer obtained by adding a small amount of monomer having a variety of functional groups to a large amount of ε-caprolactone. This patent is also problematic because the suture directly coated with the solution of polymer and drug exhibited the decrease in mechanical strength.
US Patent Application Publication No. 2004040488 discloses a suture having pores or channels in which a liquid drug is loaded, so that the liquid drug is delivered to the wound. This patent is also problematic because the tube-shaped suture, provided in the form of the drug being contained therein, undesirably decreased the mechanical strength.
Meanwhile, the drug-delivery sutures that are currently in clinical use are limited to the use in preventing infection, thereby only with the drugs, such as antibiotics. Therefore, it is necessary to develop sutures enabled with delivery of various types of drugs for many different purposes.
Given these, the present inventors have discovered a system composed of a biodegradable material, which can be loaded with diverse types of drugs, such as an anticancer agent, anti-inflammatory drug, antibiotic, etc. The system in turn, is physically adhered to the suture to ensure topical transfer of the drug, thereby improving therapeutic effects, which culminated in the present invention.